An embodiment of the present invention relates generally to a method for discriminating radioactive anomalies from naturally occurring radioactive materials, and more particularly, to a method for discriminating highly enriched uranium (HEU) or other weapons grade radioactive materials from naturally occurring radioactive materials.
There is a growing concern that terrorists or others may at some time in the near future attempt to import into the United States or some other country radioactive or nuclear material which may then be used for the construction of a nuclear weapon for carrying out terrorist objectives. One way of shipping such radioactive or nuclear material is to hide the material among or within seemingly innocuous cargo or naturally occurring radioactive materials. For example, such nuclear material could be placed within a standard, sealed cargo container of the type typically employed for shipping cargo by sea, rail, air or by truck. The nuclear material could be positioned within such a sealed cargo container, and may be shielded to avoid detection. Shielded HEU masked by naturally occurring radioactive materials is the most challenging detection problem.
It is therefore desirable to provide a reliable method of discriminating HEU or other radioactive materials of interest from naturally occurring radioactive materials.